Nationwide's economist Fionnuala Earley is the first commentator to go public on the economic consequences of the new outbreak of terrorist attacks.
It is overwhelmingly a matter of confidence, she points out. Over a quarter of a century, the IRA never succeeded in inflicting damage that impacted directly on the economy.
Two huge bombs in the City of London - admittedly timed to explode out of hours when few people were about - did spectacular damage to buildings, but not to the ability of the City and its markets to function.
Their chief effect was scare off American bankers, and doubtless other foreigners besides.
Arguably they prolonged the life of the City as a British-owned financial centre, delaying the day when Merrill Lynch mopped up Smith New Court, Warburgs was swallowed up by the Union Bank of Switzerland, Morgan Grenfell by Deutsche Bank and all the rest.
The harm they did to confidence was infinitely greater than the physical damage.
That is surely going to be the case now, the more so since the new bombers are targeting people rather than buildings. As in the '70s and '80s the confidence of foreigners is likely to prove fragile first. After all, they are here by choice and can most easily pack their bags and go off to work somewhere else - even if their employers don't make the decision for them.
If that starts to happen, the effect on modern Britain is hard to guess. It certainly won't help. We benefit hugely from our role as the prime international centre in the European time zone.
Ms Earley is concerned more directly with the housing market. So far there is no perceptible effect. Even in London estate agents report no change in the pattern of visits by would- be home-buyers.
But if the bombs continue that could change. Confidence does not exist in a vacuum. It is the product of a mix of factors and the balance between them. A terrorist campaign is just one element - how baleful probably depends on how long it persists.
Northern Rock's finance director Bob Bennett, a shrewd observer of the British economy, argues that nothing much will go wrong with the housing market and underlying confidence in it so long as employment holds up, which it should even if economic growth slips back to two per cent.
People who keep their jobs keep up their mortgage payments - and without forced sellers house price don't crash. In the early '90s many of the forced sellers were still in work. They just couldn't afford their mortgages when interest rates doubled.
That won't happen this time. Interest rates look like falling, not rising - starting next month - quite possibly touching four per cent by next summer.
On the bleaker side, everybody's family budget faces another round of nasty price increases for gas, electricity and water, plus council tax presumably. So be thankful for every minor mercy.
Gordon Brown may have postponed the worst of whatever taxes he has in mind by fudging his "golden rule". That is just as well.